The salty’s no.1 nemesis must surely be the alien like sea louse, who have been able to track down the salmonid family member’s for thousand’s of year’s in the vastness of the ocean……. The sea-louse (lepeophtheirus salmonis) reside’s in the cooler water’s of the northern hemisphere, it use’s all the migratory salmonid family for it’s life cycle. The adult female carry’s two egg string’s containing up to 180 egg’s which hatch directly into the sea, after between 5-8 day’s ( depending on water temp) the translucent, 0.5-0.6mm, planktonic hatchling’s drift along with the tide for 2-14 day’s, relying on it’s fat reserve’s as they cannot feed until their host is met, and then it will moult into the next stage enabling it to clasp onto it’s host, it’s only then it can start to graze on the host’s mucus, fin’s, blood until it get’s to 6-8mm in length, it will then attach a penetrative thread to the host, before the next stage/ moult into one of the pre-adult mobile stage’s on the host, before it moult’s into an adult to reproduce and complete the 10th stage/moult of it’s life where it will reach 5-6mm as a male and at 8-18mm as a female. Some other fact’s on lice are that a lot depend’s on 14c+ water temp,and 25%+ salinity, for growth and reproduction rate’s, when searching for a host they move vertically up in daylight, + down in the darkness though the water column, and showing more activity when sensing any movement nearby, peak activity in term’s of number’s is around May, it’s lifespan was recorded at 210 day’s to one female in laboratory condition’s, it’s still a mystery how they find their host, but find them they do!! The lice inflict serious damage on our beloved “salty’s” along with inflicting high mortality rate’s on delicate smolts, they also do a lot of unsightly damage on mature fish, along with a lot stress on them. I’ve often heard it said that salty’s enter fresh water to rid themselve’s of the lice, I’ve also read about creature’s in time’s of stress going back to their place of birth, which ever it is I’ve certainly seen salty activity to back it up……The 3lb fish above fell to a fly in a freshwater pool which the tide hit twice daily, salinity must have been very low if at all, with the river only backing up when the tide hit, it was in late May peak time for the sea lice (high infestation), although no lice were on the fish, the recent lice damage was easily seen on it’s dorsal fin, and around the vent, now I’ve often seen salty’s in this pool at the same lie and they hang around for 24-36 hour’s before disappearing, they stayed for enough time to get rid of their lice as they fall off within 20 hour’s being in fresh water, other salty’s I spotted in this pool on previous occasion’s didn’t move up the river either, as I have checked out all the other pool’s upstream, and it’s easily done as the river is no more than 3ft in it’s deepest pool’s, and fade’s into three stream’s after only a kilometer, and I never spot anything except juvenile trout from Feb-Nov, though mature spawning fish returning late Nov and are easily spotted. After many year’s observing salty’s, Seeing is believing, especially with the enigmatic sea-trout, with all it’s riddle’s, and perplexing way’s, making them the no.1 target in spring and early summer in the salt !!